Herz H7990 Series, Manual

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OPERATION

On/Off : Press “
” to turn on, press “ ” again to turn off thermostat and its output.

Setting temperature: press “
 ” to reduce temperature, press “  ” to raise temperature (0.5
℃
changed each
press)

Mode Selection: Press “ ” to change system working in cooling “ ”, heating “ ” or ventilation “ ”mode.(The

Fan speed Selection (not for
H7 990
Y/YE): Press
“ ”to select (Hi), (Med), (Low), AUTO(Auto).
In mode “AUTO”(Auto)”, the fan-speed changed automatically. Auto LOW-speed When the differential temperature
between room-temperature and setting-temperature exceed 1
℃
, Auto MED-speed When exceed 2
℃
, Auto HI-speed
When exceed 3
℃
.

Control Damper (
H7 990
Y/YE): The damper will be open when room temperature is higher than set-point in
cooling; room temperature is lower than set-point in heating, Otherwise the damper will be closed.

Control Motorized Valve under 2-pipe configuration (not for H7 990 Y/YE): If the differential temperature between
room
temperature and set-point exceed 1
℃
, FCU valve will be open; if room temperature and set-point are equal,
H 7990
DA/
DAE/DA2/DA2E will close the FCU valve with the fan still running, H
7990
DB/DBE/DB2/DB2E will close both of valve and
Fan.

Control FCU Valve under 4-pipe configuration (
H 7990
FCV2/FCV2E): In cooling, when the room temperature
is higher than set-point, the cooling Valve will be opened. Otherwise it will be closed. Heating valve is always closed.
In heating, When the room temperature is lower than set-point, the heating valve will be opened. Otherwise it will be
closed. Cooling valve is always closed.
CLOCK CALIBRATION ( -T, -T74 )

Press “M” with four seconds till to display “hh:mm” and “hh” flash, press “

” or “

” to adjust hour, press “M”,
“mm” flash, press “  ” or “  ” to adjust minute; Press “M”, “week” flash, press “  ” or “  ” to adjust Mon to Sun.
TIMER FUNCTION SETTING ( -T )

Timer on/off function: Turn on or Turn off the thermostat according to customers setting

Timer on: Press “M”, till to display “ON” and “hh” all flash, press “  ” or “  ” to adjust hour. Press “M”, “mm” flash,
press “

” or “

” to adjust minute.

Timer off: Press “M”, till to display “OFF” and “hh” which all flash, press “  ” or “  ” to adjust hour. Press “M”,
“mm” flash, press “

” or “

” to adjust minute.

Canceling timer on: Press “M”, till to display “ON” and “hh” which all flash, press “  ” or “  ” to adjust hour to
“--:--”. Press “M”, “mm” flash, press “

” or “

” to adjust minute to “--:--”.

Canceling timer off: Press “M”, till to display “OFF” and “hh” which all flash, press “  ” or “  ” to adjust hour to
“--:--”. Press “M”, “mm” flash, press “  ” or “  ” to adjust minute to “--:--”.
7 DAYS PROGRAMMING (-T74)

Divide each day of one week (7 days) into four events, set the temperature respectively to satisfy different room
temperature requirements in different time.

Power On: Press “ ” and “ ” at same time for 3 seconds till displaying “SET”, ”1” and “MON”, to set the 7days
4periods programs based on the following table. When
“hh” of “hh:mm” is flashing, ”▲”or ”▼” button to set the hours of
programming time; Press
“ ”, “mm” of “hh:mm” is flashing, “▲” or ”▼” button to set the minutes of programming time;
HERZ Armaturen Gws.m.b.H
Richard-Strauss-Strasse 22,1230 Vienna, Austria.
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